T. Ramesh1, N. Patel1, G. Aaron1, J. Warram1, E. Rosenthal1 1University Of Alabama At Birmingham,Department Of Surgery,Birmingham, AL, USA
Introduction: Minimizing surgical morbidity after local flap reconstruction is important in the management of cutaneous defects. In the past, many treatment modalities have been used to mitigate the disease burden and preserve the function of vital head and neck structures. Controversy exists in the literature regarding the effects of two such modalities—radiation and chemotherapy—on flap perfusion. Neoadjuvant treatments have the potential to cause damage to the microvasculature of the surgical bed through fibrosis, endothelial cell damage, and reduced cell proliferation, all of which increase the likelihood of postoperative flap failure. The aim of the present study is to examine the effects of neoadjuvant radiation and chemotherapy on blood perfusion following dorsal flap surgery in an athymic female mouse model.
Methods: Animals were divided into three treatment groups: No pre-flap treatment (negative control, n=4), 36-Gy electron-beam radiation administered to dorsal skin (radiation group, n=4), and 2 mg/kg intraperitoneal cisplatin (chemotherapy group, n=4). Treatments were completed on mice 15 days prior to undergoing random-pattern dorsal flap surgery with a length-to-width ratio of 4:1 (4x1cm2). Flap perfusion was assessed via laser-assisted indocyanine green dye angiography and by standard clinical assessment.
Results: LUNA perfusion imaging performed on post-operative day 1 showed 56% distal end flap perfusion relative to healthy skin in chemotherapy group mice, compared to 69% and 71% distal end perfusion in control and radiation groups, respectively. LUNA perfusion imaging performed on post-operative day 4 showed 75% and 72% perfusion relative to healthy skin in control and radiation group flaps, respectively. By post-operative day 5, all chemotherapy group flaps experienced full flap loss. In contrast, 3 of 4 control group flaps and all radiation group flaps survived to the conclusion of the experiment. Clinical assessment of flap perfusion by two physicians on post-operative day 2 revealed that elevated skin flaps of the chemotherapy group were more poorly perfused throughout than flaps in control and radiation groups.
Conclusion: Both LUNA intraoperative imaging and clinical judgment indicated that distal ends of chemotherapy group flaps were most poorly perfused. In addition, complete flap loss occurred faster in chemotherapy group mice than in radiation group and control group mice, suggesting that chemotherapy treatment has the most detrimental effect on flap viability.
